Heartful Maman The Animation ((free)) -

(2017) reveals a narrative that, while ostensibly serving the adult genre, delves into surprisingly heavy themes of grief, maternal longing, and the paralysis of trauma. Directed by Naomi Hayakawa, the series centers on Kinosaki Mao, a college student whose life is defined by a decade-long mourning for his mother. The Architecture of Grief

If you're looking for a summary, here's a breakdown that treats its plot seriously (within the genre's conventions): heartful maman the animation